Computer numerical control (CNC) machines are widely used today in nearly all aspects of manufacturing. The main benefit offered by all forms of CNC machine tools is improved automation. This improved automation reduces the amount of operator intervention related to producing workpieces and therefore reduces the costs associated with the production of workpieces.
While there are a wide variety of CNC machines that perform various tasks, one of the most common types of CNC machines is a three-axis CNC machine 1, FIG. 1. A typical three-axis CNC machine 1 includes a base 2, a table 3 and a spindle 5. A workpiece 7 (typically a flat bar stock having six faces) is secured, generally with one or more vices (not shown), to the table 3 which is moveable along two axis A and B with respect to the base 2 (typically left to right and front to back respectively).
A motor 4 drives the spindle 5 which includes a removable tool 6 (typically an end mill or a drill bit) used to perform the machining. Multiple tools 6 (for example, various sizes and types of drill bits) are generally stored on a tool head (not shown). The CNC machine 1 may be programmed to change tools 6 during the machining process as necessary.
The spindle 5 typically moves in a third axis C with respect to the base 2 (typically up and down). Thus, the three axis in a typical three-axis CNC machine 1 are: A (the table 3 moving left/right); B (the table 3 moving back/forward); and C (the spindle 5 moving up/down).
While these known three-axis CNC machines 1 are common and fairly inexpensive, they suffer from several known problems. For example, during the machining of a workpiece 7, it is often necessary to perform several functions. For example, it is often necessary to cut the length of the bar stock to a desired length, create holes, channels, threads, etc. One problem with the known three-axis CNC machines 1 is that each workpiece 7 must be loaded onto a table 3 individually. Not only is the process of loading multiple tables 3 time-consuming since each table 3 must be loaded by hand, but it is also equipment intensive since it requires a large number of tables 3.
While the known three-axis CNC machines 1 are generally quite effective at performing machining tasks, it is often necessary to machine the workpiece 7 along multiple faces (e.g., the top, bottom, sides, and/or the ends). Unfortunately, traditional three-axis CNC machines 1 are only capable of machining one face of the workpiece 7 at time. As a result, the workpiece 7 must be removed from the table 3, re-indexed, and secured back on the table 3. Having to re-index the workpiece 7 has several downsides.
Firstly, re-indexing the workpiece 7 is time consuming. When producing multiple workpieces 7 having machining on more than one face, the CNC machine 1 must first machine a first face of all the workpieces 7 to be created. Next, a human/operator must reload all the unfinished workpieces 7 back into tables 3 and re-index the workpieces 7 (i.e., orient the workpieces 7 properly). The reloading/re-indexing process includes several drawbacks.
One problem is that the reloading/re-indexing process requires multiple tables 3 to be reloaded. As discussed above, the process of reloading multiple tables 3 is not only time consuming, but also equipment intensive. Moreover, should the CNC machine finish machining the first faces of the workpieces 7 during off-hours (i.e., when an operator is not present), then the CNC machine 1 must sit idle until it is reloaded.
Another problem is that the human/operator must re-index each workpiece 7 separately during the reloading process. This greatly increases the likelihood that a workpiece 7 may be improperly indexed and be destroyed. Lastly, the reloading/re-indexing process requires the CNC machine 1 to be shut down or stopped, thus reducing the overall efficiency of the CNC machine 1.
While four and five axis CNC machines that are capable of machining more than one face at a time are known, these known machines are very expensive. Additionally, these CNC machines also require specially designed stand-alone CNC machines. As a result, the existing traditional three-axis CNC machines 1 cannot be retrofitted to perform multi-faced machining. Because of this, many companies who have a large number of traditional three-axis CNC machines 1 are not willing to get rid of their existing CNC machines.
Accordingly, what is needed is an apparatus that solves the above problems and that is capable of machining more than one face of a workpiece. The apparatus should preferably be capable of being retrofitted with existing three-axis CNC machines. The apparatus should also preferably be capable automatically loading a bar stock such that individual workpieces do not have to be loaded into a table.